Etching Method For A Structure Pattern Layer Having A First Material and Second Material

Abstract

Provided is a method of plasma etching on a substrate using an etchant gas mixture to meet integration objectives, the method comprising: disposing a substrate having a structure pattern layer, a neutral layer, and an underlying layer, the structure pattern layer comprising a first material and a second material and the underlying layer comprising a silicon anti-reflective (SiARC) layer, a spin-on carbon hardmask (CHM) layer, an oxide layer, and a target layer; performing an first etch process to selectively remove the second material and the neutral layer using a first etchant gas mixture to form a first pattern; performing an second etch process to selectively remove the SiARC layer to form a second pattern; performing an third etch process to selectively remove the CHM layer to form a third pattern; concurrently controlling selected two or more operating variables wherein the first etchant gas include oxygen and sulfur-containing gases.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Pursuant to 37 C.F.R §1.78(a)(4), this application claims the benefit of and priority to co-pending U.S. Provisional Application No. 62 / 364,149, filed Jul. 9, 2016, and U.S. Provisional Application No. 62 / 255,770, filed Nov. 16, 2015, which is expressly incorporated by reference herein in its entirety.FIELD OF THE INVENTION[0002]The invention relates to a method for selectively etching a structure pattern layer having a first material and a second material and specifically to etching such layers with enhanced etch sensitivity with an etchant gas mixture resulting in improved line edge roughness (LER) and line width roughness (LWR) of the target structure.BACKGROUND OF THE INVENTION[0003]The need to remain competitive in cost and performance in the production of semiconductor devices has caused a continuous increase in device density of integrated circuits. To accomplish higher integration and miniaturization in a semiconductor integrated ...

AI Technical Summary

Benefits of technology

The patent describes a method of plasma etching on a substrate using a specific mix of gases to achieve specific objectives. The method involves selectively removing different layers of materials on the substrate to create patterns. The system includes a plasma etch system and a controller to manage the process. The resulting patterns have improved roughness and width. The technical effect is to create more precise and uniform patterns on substrates using plasma etching.

Problems solved by technology

When applied in a thin film, the geometric confinement may pose additional boundary conditions that may limit the numbers of phases.

However, when removing the PMMA portion from the polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) layer to leave behind a polystyrene (PS) pattern, conventional etching techniques have suffered.

Due to the organic nature of both materials, and their similarities, developing an etch chemistry with suitable etch selectivity has been challenging.

Furthermore, conventional etch processes produce pattern defectivity, such as line edge roughness / line width roughness (LER / LWR), that are unacceptable as per the semiconductor device performance requirements.

The current methods do not provide the LER and the LWR that are required as the need for higher density patterns increases.

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